Film- and fiber-forming solutions of polyhydrazides are known in the art, e.g., as described in Frazer U.S. Pat. No. 3,130,182, U.S. Pat. No. 3,130,183, U.S. Pat. No. 3,536,651 and in Schopf et al. U.S. Pat. No. 3,607,810. Optically anisotropic solutions of aromatic polyamides are described in, e.g., Kwolek U.S. Pat. No. 3,671,542.